If you enter required parameter in URL, it trigger a search on website. (URL example: https://subscene.com/subtitles/title?q=Avatar).
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/427315/1220388/URL%20Based%20Search%20for%20Some%20Websites.js